Operating mechanism for elevator retiring cams



Jan. 13, 1942. c. J ANDERSON 2,269,504 OPERATING MECHANISM FOR ELEVATOR RETIRING CAMs Filed March 18, 1940 Patented Jan. 13, 1942 OPERATING MECHANISM FOR ELEVATOR RETIRING CAMS Carl J. Anderson, Chicago, Ill., assignor to. C. J. Q

Anderson & Co., Chicago, 111., a corporation of Illinois Application March 18, 1940, Serial No. 324,700

9 Claims. (Cl. 187-51) The present invention relates in general to operating mechanism for operating the retiring cams of elevators.

An object of the present invention is to provide improved operating mechanism for elevator retiring cams of simplified and efiicient construction.

Another object is to provide operating mechanism of such character that the usual air or oil dash-pot is eliminated.

Another object is to provide a loose coupling between the cam operating motor and the retiring cam so that no jar is transmitted to the retiring cam during its operation.

A further object is to provide retiring cam operating mechanism that will function silently, without chattering.

There are other objects of my invention which, together with the foregoing, will be described in the detailed specification that is to follow, taken in conjunction with the accompanying drawings and forming a part thereof.

As is well known, elevator cabs carry retiring cams which are operated when the elevator stops at a floor level to unlock the elevator doors. To bring about the operation of the retiring cam, an electric motor is employed. An oil or air dash-pot is usually associated with this operating mechanism to prevent chattering and to reduce the noise of operation.

In the present invention I employ a specially designed cam with a lost motion connection between it and the motor whereby the same results are accomplished in a simplified and efiicient manner.

Referring now to the drawing in which I have illustrated an embodiment of my invention:

Fig. 1 is a side elevation of the retiring cam and its operating mechanism which is usually mounted on the top of the elevator car or cab.

I Fig. 2 is a top plan view of a portion of the cam operating motor and the lost motion connection of my invention.

Fig. 3 is an enlarged sectional elevation of certain portions of my invention taken along the line 3-3 of Fig. 2, looking in th direction of the arrows.

In the drawing like reference characters apply to similar parts throughout.

The reference character gen rally designates the retiring cam and its associated mechanism which is carried by the cab in any usual or well-known manner.

The construction of the retiring; cam may be of. a y usual r l nown ype and consists es-,

sentially of an operating member ll, supported by pivotally mounted brackets I2 and I3 upon a base member J4. A roller I5 is adapted to be engaged by the operating member II in its extended position and bring about the unlocking of the elevator door.

An operating link l6 connects the bracket |3 to an angular lever H, which is pivotally supported at I8 on a bracket |9 secured to the base M. The pivotal movement of the lever I1 is adapted to change the position of the operating member ll of the cam from its retired position (shownby the dotted lines) to its operating position' in engagement with the roller l5.

An operating rod connects the bracket I! with a lever 2|, which is pivoted at 22 to the base plate 23 of the motor 24, which is mounted on the top of the elevator cab.

The operating rod 20 is pivotally secured to the lever 2| through a rotatable bracket 25. The bracket 25 also supports a shaft 21 carrying a roller 28 formed from rubber or other suitable resilient material.v Roller 28 is adapted to engage an operating surface 29 of a specially shaped operating cam 3|] (see Fig. 3).

The operating cam 30 is pivoted upon a stub shaft 3|, through a bushing 32. The stub shaft 3| is carried by an L shaped bracket 33 mounted upon the base 23, The upper end of the bracket is provided with an extension 34 supporting an operating cam stop 35 which may be made of rubber or other suitable material. Cam stop 35 is mounted upon the end 34 of the bracket 33 by means of a bolt 36. r

The motor 24 is provided with a shaft 38 which has secured to it a crank arm 39 by means of a set screw 40. The crank arm 39 is provided with a resilient roller 4| which engages the inner surface of the operating cam 30.

In the position shown in Fig. 1 the retiring cam is in extended position, which it assumes when the motor 24 is deenergized. The motor 24 is a so-called torque motor, which means that it will lock in any given position when energized when an unusual load is put upon it which occurs when the cam 30 is moved into operative position.

The motor 24 is connected to the car control so that when the controller is moved to start the car, the motor 24 is energized. This brings about the rotation of the motor shaft 38 and the crank arm 4|, moving the cam 30 until the surface 44 thereof is in contact with the roller 28.

This brings about the horizontal movement of the perating bar 2|! and the retirement oft-he into extended position. bringing the end surface of the operating cam 30 against th cam sto 35. The crank arm 4| is then in the position shown by the dotted lines in Fig. 3.

More or less abrupt stopping of the movement of the retiring cam by the operating cam 45 engaging the cam stop 35 is ordinarily compensated for by means of an oil dash-pot or some other similar mechanism.

' In this instance the crank arm 4| moves from the position shown by the full lines of Fig. 3 to that shown by the dotted lines. The crank arm 4| then may rebound without bringing about any movement of the operating cam 30. This lost motion connection not only absorbs some of the momentum and cushions the shock, but prevents any-chattering of the retiring cam and door lock itself which'would otherwise occur were the motor shaft connected directly to the retiring cam mechanism.

The resilient roller 4| carried by the crank arm tends to absorb any shock in connection with the abrupt stopping of the operating cam, which stopping is cushioned to a certain extent by the resiliency of the cam stop 35.

The crank arm 4| is so mounted on shaft 38 that it will return to the position shown in Fig. 3 ready to operate the cam 30 without any jar upon subsequent energization of the motor 24. This provision is important since it eliminates lost motion in the connection between the motor 24 and the retiring cam when it is necessary to retract it thereby eliminating any noise or ar.

Since the motor itself does not energize in reverse to bring about the extension of the retiring cam, there is no lost motion in the connection between the crank arm 4| and the operating cam 30 until the surface 45 encounters the cam stop 35 when the crank arm 4| assumes the dotted position shown in Fig. 3. As before mentioned, this lost motion provision is then operated to cushion the shock of the momentum of the movement of the retiring cam to prevent chattering and to eliminate explosive oil or air dash-pots or other cushioning mechanism.

Other advantages of using this cam operating mechanism are that there is no necessity for adjusting it, and there is no maintenance except for the occasional replacement of the resilient roller 4| and the cam stop 35.

In the usual practice where there is a direct connection between the motor 24 and the retiring cam dash-pots or some other similar mechanism requiring much adjustment and high maintenance are usually employed. Obviously, it is important that the retiring cam operates smoothly and efliciently, since this is the mechanism by which the elevator .door locks are operated, and this, in turn, is interlocked with'th operating circuits for the elevator itself.

My invention may be variously modified withut departing from the spirit and scope thereof, a indicated by the appended claims.

the motor I claim:

1. In an elevator system, an elevator cab, a retiring cam carried by said cab and adapted to cooperate with door locks in the elevator hatchway, a motor, mechanism connecting said motor and cam whereby the same may be extended and retracted and means for introducing lost motion into said connections when the mechanism is operated by said motor to operate the cam into its retracted position, said means being operative to operate said mechanism to advance said cam without said lost motion.

- 2. An elevator having a retiring cam mounted thereon, mechanism for extending and retracting said cam, a motor for operating said mechanism, an operating cam connecting said motor and mechanism adapted to couple the motor and mechanism together when revolved in one directionand to introduce lost motion in said connection when revolved in the other direction, comprising means driven by said motor through an arcuate pathfand an arcuate guideway on said operating cam receiving said driven means.

3. Operating mechanism for bringing about the extension and retraction of a retiring cam'comprising a motor, means for extending and retracting said cam, a shaft for said motor, a crank arm mounted'on'said shaft, an operating cam pivotally mounted adjacent to said crank arm and adapted to be operated thereby, and a roller adapted to be engaged by said operating cam and connected to said means.

4. Operating mechanism for bringing about the extension and retraction of a retiring cam comprising a motor, rigid means for extending and retracting said'cam, an operating cam adapted to bring about the operation of said rigid means, a shaft for said motor and a crank arm secured to said shaft adapted to operate said operating cam.

5. Operating mechanism for bringing about the extension and retraction of a retiring cam comprising a motor, rigid means for extending and retracting said cam, an operating cam adapted to bring about the operation of said rigid means, a shaft for said motor and a crank arm secured to said shaft adapted to operate said operating cam, said operating cam being so shaped that movement of the crank arm in one direction introduces lost motionin said cam operation.

6. Operating mechanism for bringing about the extension and retraction of a retiring cam comprising a motor, rigid means for extending and retracting said cam, an operating cam adapted to bring about the operation of said rigid means, a shaft for said motor and a crank arm secured to said shaft adapted to operate said operating cam, said operating cam being so shaped that movement of the crank arm in one direction introduces lost motion in said cam operation and said crank arm being mounted on the motor shaft so that rotation of said shaft brings said arm into operative position against said cam.

7. Operating mechanism for bringing about the extension and retraction of a retiring cam comprising a motor, means for extending and retracting said cam, an operating cam adapted to bring about the operation of said means, a shaft for said motor and a'crank arm secured to said shaft adapted to operate said operating cam, said operating cam being so shaped that movement of the crank arm in one direction introduces lost motion in said cam operation and said crank being ounted on the motor shaft so that said 10st motion is eliminated by gravitational rota- 10 motion.

brings it into operative position against the operating cam.

9. In a system of the class described, a retiring cam adapted to cooperate with door looks, a motor for advancing and retracting said cam, means connecting said motor and cam, and means for introducing lost motion into said connection when said cam is retracted by said motor, said means being operative to advance said cam without lost CARL J. ANDERSON 

